with Dr. James Brooks (BD Biosciences) Improvements in cell culture media and supplementation have enabled significant advancements in bioproduction titers. But optimization to meet the specific needs of individual production cell lines is key to achieving desired production and protein quality, especially for biosimilars. Not only is it desirable to achieve cost-effective levels of production, but quality characteristics also are essential — and for biosimilars must closely resemble those of the originator molecules. Fully chemically defined (CD) media formulations are…
Analytical
Uniting Small-Molecule and Biologic Drug Perspectives: Analytical Characterization and Regulatory Considerations for Antibody–Drug Conjugates
Cosponsored by CASSS (an international separation science society) and the US Food and Drug Administration (FDA), the January 2010 CMC Strategy Forum explored antibody–drug conjugates (ADCs), which are monoclonal antibodies (MAbs) coupled to cytotoxic agents. The ADC platform of products is being used more and more for clinical evaluation in oncology. More than a dozen companies are developing several types, including products conjugated with calicheamicin, auristatins, and maytansinoids. Such products use the specificity of a MAb to deliver a cytotoxic…
Glycosylation of Therapeutic Proteins: Current Understanding of Structure–Function Relationships
A CMC Strategy Forum held in Washington, DC, on Sunday 28 January 2007 focused on two topics related to protein structure and function (1). First, analytical techniques used in the glycan analysis characterization included recent advances and correlations among the various tools. And second, current understanding of glycosylation’s functional relevance to therapeutic proteins was discussed in the context of its effects on biological activity, pharmacokinetics, and Fc effector functions (for monoclonal antibodies, MAbs). Progress has been made in the field…
Analysis and Structure Characterization of Monoclonal Antibodies
On 6 January 2003, 129 attendees participated in the second Well-Characterized Biotechnology Product (WCBP) Chemistry and Manufacturing Controls (CMC) strategy forum, titled “Analysis and Structure Characterization of Monoclonal Antibodies (MAbs),†held in San Francisco to discuss lot release and characterization test issues specific to MAbs (1). The objective of the meeting was twofold: to identify a “core†set of assays most useful for lot-release testing of MAbs and to define a mechanism for selecting appropriate potency tests. Two separate workshops…
Lot Release and Characterization Testing of Live-Virus–Based Vaccines and Gene Therapy Products
The January 2005 CMC Strategy Forum was devoted to a discussion of live virus vaccines and viral vectors used for gene therapy. The purpose of the meeting was to determine whether consensus positions could be reached among the delegates regarding lot release, stability, characterization, and comparability testing. Part 1 of this two-part report on that meeting describes factors influencing the choices of lot-release assays for vaccines and gene-therapy products (1). Part 2 presents potency testing, characterization, and comparability studies, including…
Biophysical Analysis: A Paradigm Shift in the Characterization of Protein-Based Biological Products
Generating a stable environment for a biopharmaceutical drug substance is a critical step for ensuring a long drug-product shelf life (1–6). This process begins early in development with preformulation screening. Some of the most critical parameters to maintaining potency and activity are protein conformation (tertiary or three-dimensional (3-D) structure), folding (secondary structure), and proper subunit association (quaternary structure). Collectively, those are known as higher-order structure (HOS) and can be highly influenced by the formulation environment of a protein drug product.…
Variables in “Passive†Cryopreservative Methods: Standardizing Cell-Based Assays By Reducing Cryopreservation-Induced Variability
Cells have become essential in modern medicine as therapies, vehicles for producing high‑value therapeutics, and tools for high‑throughput screening of pharmaceutical compounds. In the latter area, more than 50% of drug discovery screens use cell‑based assays, predominantly targeting receptors and ion channels using fluorescence‑based measurements, in either or both high‑ throughput and high‑content formats (1). Alongside a cell therapy market estimated to be worth some $5.0 billion by 2015 (2), the larger cell‑ based screening market is estimated to be…
Development of a High-Throughput Formulation Screening Platform for Monoclonal Antibodies
The goal of formulation development for therapeutic proteins is to find conditions under which a protein remains stable during storage, transport, and delivery to patients. Both chemical and physical stability must be considered. Chemical stability is related to the rates of chemical modification to a protein molecule such as deamidation of aspargine residues and oxidation of methionine residues (1, 2). Particularly important to control if they affect biological function, those modifications could also lead to changes in conformation or half-life…
Fluid Dynamics of a Single-Use, Stirred-Tank Bioreactor for Mammalian Cell Culture
The benefits of single-use technologies in both upstream and downstream operations are now widely acknowledged by the biopharmaceutical industry, and have led to radical changes in the design and operation of many bioprocesses. Those changes typically provide more robust processes and increased production flexibility. For mammalian cell culture, cleanable multiuse glass or stainless steel stirred-tank reactors (STRs) have been used successfully for growth of suspension-adapted cell lines in both small- and large-scale systems. However, achieving the same or better performance…
Meeting Lot-Size Challenges of Manufacturing Adherent Cells for Therapy
Adherent cells such as adult primary cell lines and human multipotent (MSCs) and pluripotent stem cells (hPSCs) present a manufacturing challenge as lot sizes increase from 109 (billions) to 1012 (trillions) cells (1). Typically, manufacturing platforms are good for one log of expansion. So new methods will be required to achieve commercially relevant lot sizes. Traditional two-dimensional culture methods have been used to grow anchorage-dependent cell types. Although such methods are reliable and well defined, they are very labor intensive…